Caladenia calcicola, commonly known as the Bats Ridges spider orchid, is a plant in the orchid family Orchidaceae and is endemic to a small area near the Victoria - South Australia border. It is a ground orchid with a single hairy leaf and one or two glossy, pale yellow flowers with maroon markings.
Caladenia calcicola is a terrestrial, perennial, deciduous herb with an underground tuber and a single lance-shaped, hairy leaf measuring to in length and to in width. A single flower, approximately to wide, is borne on a hairy spike ranging from to in height. Occasionally, a second flower is present, and the spike may reach up to in height.
The lateral sepals and petals are pale, glossy yellow with a prominent red stripe along the center. The lateral sepals spread widely and curve downwards, long and wide, tapering to thread-like, glandular tips that are yellow to reddish and long. The petals are slightly shorter than the sepals and also taper to fine points. The labellum is long and wide when flattened. It is partly red with a yellowish-cream coloration near the base. The sides of the labellum bear linear teeth up to long, and gradually decrease in size toward the tip. Four to six rows of flattened calli run along the mid-line of the labellumâÂÂs surface. Flowering occurs from mid-September to early November.
Caladenia calcicola was first formally described in 1986 by Geoffrey Carr in the journal Muelleria from a specimen collected about west of Portland. The specific epithet (calcicola) is derived from Latin words meaning "lime" and "dweller".
This caladenia grows on low limestone ridges in a few areas west of Portland and a short distance into South Australia.
Caladenia calcicola is classified as "vulnerable" under the Commonwealth Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC) Act, as "Endangered" under the South Australian National Parks and Wildlife Act and as "Threatened" under the Victorian Government Flora and Fauna Guarantee Act 1988. The total population in 2007 was estimated to be less than 300.